🥣 Kashk

Kashk is a dried fermented dairy product from Iran and the wider Middle East: salty balls or oval, tapering lumps of strained sour milk. Traditionally it is made mostly from raw sheep's milk, and also from the buttermilk left over after churning butter: the buttermilk is soured, salted and dried. Dry kashk is very dense, so it is soaked and softened before use.

Today kashk comes in two forms. Traditional dry kashk keeps for a long time at room temperature without losing its nutrients. Industrial liquid kashk is made differently: the milk is pasteurized, fermented into yogurt, concentrated and heated with salt. According to Iranian producers, 100 kg of milk yields about 33 kg of kashk and 67 kg of whey. Preservatives are not allowed in kashk.

Kashk is a true milk-protein concentrate: dry kashk from different Iranian provinces contains 39.6 to 67.8% protein. It also provides B vitamins, calcium and potassium, and researchers have isolated lactic acid bacteria with probiotic properties from it. In Iranian cooking, kashk goes into many dishes as a sour and salty dressing.

Kashk or yogurt? Liquid kashk begins as yogurt: the milk is pasteurized, fermented, concentrated and heated with salt, so 100 kg of milk yields about 33 kg of kashk and 67 kg of whey. Dry kashk is older: strained sour sheep's milk, or buttermilk left after churning, salted and dried into hard lumps. It is closer to Central Asian kurt and Jordanian jameed than to yogurt, and it is used as a sour, salty dressing, not as a snack or a breakfast dairy.

There is no protected label for kashk, so go by the name on the pack: “kashk”, in dry lumps or as a liquid. The ingredients should be milk and salt, and preservatives are not allowed in kashk. Compare the salt figure on the label, because kashk is a seasoning. It is sold in Iranian and Middle Eastern food shops and larger supermarkets with a world-food aisle; liquid kashk belongs in the refrigerator, dry kashk in a dry cupboard.

Why it matters to you. Kashk is very salty: samples of liquid kashk from Tehran supermarkets averaged 2.78 g of salt per 100 g, while WHO advises adults to eat less than 5 g of salt a day. So treat kashk as a seasoning rather than a main dish, and don't add extra salt to food you put it in. Keep liquid kashk in the refrigerator and dry kashk in a dry place, and soak it before use.